Liquid heating device



July 1, 1958 J. L. PET-rrr Erm. 2,841,136

LIQUID HEATING DEVICE INVENToRs JC L. .Pfff/2' United States Patent LIQUID HEATING DEVICE Jack L. Pettit, Florham Park, and Andrew J. Kelly, Westfield, N. J., assignors to Metalwa'sh Machinery Company, Elizabeth, N. I., a copartnership Application December 13, 1954, Serial No. 474,848

1 Claim. (Cl. 126-350) The present invention relates to an improved liquid heating device of the direct heating type having particular utility in industrial spray washers.

In industrial spraywashing it is conventional practice to convey the work to be washed through a washing chamber where it is sprayed with hot washing solution. The washing solution is then carried to a heater for reheating and then returned to the washing chamber.

Industrial washers having heaters of the direct heating type are known in the art. They have been found to be quite useful and very eficient in their transfer of heat to the washing liquid. However, these heaters are limited in their manner of use by virtue of their construction.

It is an object of the present invention to provide a novel direct re heater.

It is a further object of the present invention to provide a liquid heating device with a heater wherein washing solution is in contact with the housing surrounding the burner to effect heat transfer from the housing to the solution whereby the housing is prevented from burning.

It is also an object of the present invention to provide means whereby the washing solution in the spray cham- `ber is commingled with the hot gases from the heater to effect the heating of said solution.

It is another object of this invention to provide a heater for or liquid heating device that is inexpensive to manufacture and simple to maintain.

Other and more detailed objects of the invention will become more apparent from a consideration of the following specification, the appended claim and the accompanying drawings, wherein:

Figure 1 is a front view of a washer embodied in the present invention;

Figure 2 is a cross section of Figure l taken through line 2--2;

Figure 3 is a perspective view of a hood which is a feature embodied in the present invention.

Referring now to the drawings, wherein the same numerals designate the same structure in the various views, a preferred embodiment of the invention is shown inFigures l and 2. This comprises a washing or spray chamber 1, and heating and storage tank 2 disposed beneath chamber 1, a heating tube 3 located within storage tank 2, and a conduit 4 connecting tank 2 with chamber 1. Conduit 4 serves to convey heating washing liquid from tank 2 to the spray system contained in chamber 1.

More particularly, washing chamber 1 comprises a generally rectangular box having a front wall 5, a top wall 7, a back wall 6 and side walls 6a, 6b. Closeable openings (not shown) are provided in the side walls of chamber 1 to allow yfor the conveyance of the work to be washed.

Two rows of vertically extending spray pipes 36 having spaced spray holes or nozzles 37 are disposed within chamber 1. Spray pipes 36 are connected to conduit 4 through manifold 8 and pipe sections 39 by right angle pipe joint 9. Manifold 8 comprises a series of pipe sec- CTI tions connected to each other by pipe joints 38 to form an H-shaped system. Manifold 8 may be disposed horizontally near the bottom of chamber 1 and in a plane which is parallel to roof 7 and the short axis of chamber 1. Pipe joints 38 may also be provided with openings to receive spray pipes 36'and to preferably although not necessarily maintain them in a vertical position. The spray system is supported in wall 5 at joint 35.

Two right angle braces 10 are spaced apart and secured at the bottom of chamber 1 to front Wall 5 and back wall 6, as illustrated in the drawing. Hood 11 is secured to braces itl in any suitable manner to provide a tortuous passageway between heating tube 3 and washing chamber 1 for the conveyance of hot gases therethrough. A tortuous passageway is also thus provided between heating tube 3 and tank 2.

Hood 11 (see Fig. 3) comprises a generally rectangular box open at the bottom and lhaving a pitched roof. It comprises two angularly disposed members 12 from which depend front and back skirts 14 and side skirts 13. More particularly storage tank 2 comprises a front wall 15, a top wall or roof 15a, a back wall 15b, a bottom wall 15C and side walls 18 and 18a.

Washing chamber 1 is disposed above and at the back of storage and heating tank 2 and is secured thereto in any `suitable manner. Washing chamber 1 may be made integral with tank 2 as illustrated in Figure 2.

Storage and heating tank 2 may have a rectangular boxlike construction and is preferably of larger volume than washing chamber l. lt is provided with an opening in the rear of its roof which communicates with Washing chamber 1. Tank 2 is also provided with an opening 16 in its front wall 15 to accommodate heating tube Si. In the side wall 18 an opening is provided to receive conduit 4. A liquid level indicator 19 may be secured to a wall or tank 2 or any other convenient place to advise the operator as to the level of washing liquid in tank 2.

Heating tube 3 comprises an elongated tubular member which may be' of any desired cross section. The illustrated embodiment is circular in ycross section. It is made of any suitable material, preferably of steel or cast iron which is readily replaced. In a preferred embodiment shown in Figures l and 2 the terminal portion 20 of tube 3 is disposed at right angles to the long axis of the tube. The open end 21 of heating tube 3 is located beneath and adjacent hood 11 so that ame and gases issuing from heating tube 3 through opening 21 are deflected around hood 11 and wash liquid descending from chamber 1 is deflected away from opening 21.

Heater 3 is connected to any suitable fuel source by collar 22. The assembly for providing a jet ame to heater 3 is generally represented at 23. The necessary construction and the nature of the fuel necessary to provide the jet flame used in the present invention are of any known type and do not form part of the present invention.

In a preferred embodiment of the present invention as illustrated in Figures l and 2 heating tube 3 is disposed within tank 2 so that it is substantially submerged in the washing liquid 24 contained in said tank. This arrangement adds the extra advantage of being able to further heat the washing liquid by direct contact with the hot tube while it is in storage waiting to be recycled for re-use. The tube is also prevented from burning out by the cooling effect of the washing liquid.

As noted above lconduit 4 is used to convey washing liquid from heater and storage tank 2 to washing chamber 1. For this purpose pump 25 is provided in conduit 4 which pumps liquid from tank 2 to washing chamber l. The capacity of pump 255 is preferably such that the liquid is quickly recycled. Conduit 4 is also provided with valve 26 to cut olf the flow of wash liquid from A"estingue tank 2 to washing chamber' 1 if this flow is ever not desired. Y

ln operation, tank 2 is filled with washing liquid to any desired level. ln the modification of this invention illustrated in Figures l and 2 the heating 'tube is sub stantially submerged in the washing liquid. Valve 26 isV opened and pump 25 is started. Washing liquid is thus rapidly conveyed through conduit d to spray pipes 34 and spray holes or nozzles 37 maintained within the washing chamber. The work inside the washing chamber is bathed by the spray of washing iiquid. The burner of heating tube 3 is turned on and the het gases issuing from its open end are deflected around hood 11 and ascend into washing chamber 1. Here the gases are intimately commingied with the spray of washing liq- Y' uid. By this intimate contact and commingliug thc washing liquid is heated very effectively and efficiently. The gases continue to rise through the washing chamber and are finally vented through a vent (not shown) in said chamber.

The washing liquid descends through washing chamber 1 to tank 2. Much of the washing liquid strikes hood il and is filmed over the inclined surface of the hood as it descends into tank 2. The Washing liquid is then rapidly recycled to washing chamber 1 through pump 25 and conduit 4. For this purpose, as mentioned above, pump 27S is a high capacity pump.

The heating tube and their associated hoods of the present invention are prevented from burning out by using the washing liquid as a coolant.

In the modification of this invention illustrated in Figures l and 2 substantially all of the heating tube is maintained below the washing liquid level in tank 2. The heating tube is thus effectively cooled by direct contact with a relatively large body of washing liquid.

In the preferred embodiment illustrated hood 11 is cooled by the washing liquid that descends through the washing tank and is filmed over the inclined surfaces of the hood.

Although the coolant function of the washing liquid as it contacts various parts of the heating tube and hood have been emphasized above, it is to be understood that there also results a corresponding heating of the washing liquid. There is thus provided auxiliary heating means for heating the washing liquid.

The operation of the present invention may proceedy either intermittently or continuously. Preferably it is operated in a continuous manner as the work is being conveyed through the apparatus.

Structures embodied in the present invention may be used in any washing process. However, they are of particular benefit in processes wherein the washing liquids contain substances which tend to coat the heating tubes, such as a phosphate solution. Where a heating tube becomes coated with these materials there results a poor heat transfer through the heater walls and a very ineflicient use of the heat generated within the tube. The present invention avoids this inefficiency by the intimate commingling of the gases issuing from the end of the heating tube of this invention with a spray of washing liquid. v

Any suitable material may be used to construct the various parts of the equipment embodied in the present invention. Those skilledin the art are well advised as 4 to the requirements of the various parts and the details as to the kinds of materials to be' used are available.

It will be readily appreciated by those skilled in the art that numerous modifications and changes may be made Without departing from the spirit of the present invention. For example, although the spray system has been illustrated as comprising two parallel rows of vertically extending pipes mounted on an H shaped manifold a single row of pipes or several rows of pipes mounted on manifolds of various shapes may be substituted therefor. Furthermore, hoods of various construction may be substituted for the hood specifically shown in the drawings. A hood comprising a single inclined member properly placed could be substituted for the hood specifically illustrated.

The general shape of the various tanks and conduits may be changed Without departing from the spirit of the invention. The shape of the heating tube may be changed so that it is rectangular or square in cross sections. Y

It is obvious therefore that the changes noted above and many others may be made without departing from the spirit of the present invention.

We have described what we believe to be the best embodiment of our invention. We do not wish, however, to be confined to the embodiment shown, but what we desire to cover by Letters Patent is set forth in the appended claim.

We claim:

In a liquid heating device having a solution storage tank, said tank including a front wall, a back Wall, a top wall, a bottom wall and two side walls, a spray chamber having a front wall, a top wall, a back Wall and two side walls disposed above said storage tank, said spry chamber being integrally fastened to said tank top wall atv its lower end and in open communication with said storage tank, a pump connected through the lower portion of one of said side walls to said storage tank, a conduit connecting said pump with said spray chamber whereby liquid may be circulated from said storage tank through said pump to said spray chamber, a pluralityy of vertically extending pipes within said spray chamber connected to said conduit, a plurality of spray holes in said pipes, a tubular heater extending through an opening in the front wall of said storage tank substantially horizontally across said storage tank below the liquid level therein, one end of said tubular heater adapted to be aixed by a collar to a fuel supply, the other end of said heater being turned upwardly substantially vertically and terminating in the lower portion of said spray chamber, a hood disposed above said vertical termination of said tubular heater, two brackets secured to said front and said back walls of said spray chamber to support said hood, said hood being provided with inclined surfaces so that liquid accumulating thereon runs down said surface into said storage tank for recirculation and means for providing a llame jet through said collar into said tubular heater.

References Cited in the file of this patent UNITED STATES PATENTS 

